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Shaji K. Kumar, MD
Shaji K. Kumar, MD
Posted: Wednesday, June 12, 2024
A multicenter study performed by Saurabh Zanwar, MD, of the Mayo Clinic, Rochester, Minnesota, and colleagues evaluated the use of the chimeric antigen receptor (CAR) T-cell therapy idecabtagene vicleucel in patients with multiple myeloma who have extramedullary disease because the agent has demonstrated efficacy in relapsed or refractory multiple myeloma. The results of this study, which demonstrated poorer progression-free survival rates with extramedullary disease than without extramedullary disease, were presented during the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 7508).
A total of 351 patients with relapsed or refractory multiple myeloma were recruited from 11 academic centers in the United States. Participants were evaluated for the presence of extramedullary disease and were administered idecabtagene vicleucel. True extramedullary disease (n = 84) was defined as having visceral or soft-tissue lesions that were noncontiguous from bony lesions; paraskeletal disease was evidence of no extramedullary disease (n = 267).
The median follow-up was 18.2 months. The objective response rates among patients with and without extramedullary disease were 58% and 69%, respectively. Patients with extramedullary disease had lower rates of complete response or rates higher than those without extramedullary disease at both day 30 (16% vs 24%) and day 90 (52% vs 82%). Median progression-free survival rates were significantly improved among patients without extramedullary disease compared with those who had extramedullary disease (P < .0001). Multivariable analysis revealed extramedullary disease to be an independent predictor of inferior progression-free survival (P < .001).
Among individuals with extramedullary disease, the type of disease progression was comparable; hematologic and extramedullary site disease progression patterns (57%) were more prevalent than hematologic (22%) or extramedullary site (21%) disease progression alone. Of note, the median overall survival was not reached and 26.9 months in the extramedullary and nonextramedullary groups, respectively (P = .006). Rates of grade 2 or higher cytokine-release syndrome were similar between the arms.
Disclosure: Dr. Zanwar reported no conflicts of interest. For full disclosures of the other study authors, visit coi.asco.org.
